Method of forming threaded die castings



Dec. 25, 195} 1.. H. MORIN 2,579,952 METHOD OF FORMING THREADED D IE CASTINGS Fi'led June 16, 1950 I 3 Sheets-Sheet 1 INVENTOR Lav/6 NOR/N LL HQ MORIN METHOD OF FORMING THREADED DIE CASTINGS Dec. 25, 1951 I5 Sheets-Sheet 2 Filed'June 16, 1950 INVENT LOUIS H. M

ATTORN Y Dec. 25, 1951 MORlN 2,579,952

METHOD OF FORMING THREADED DIE CASTINGS Filed June 16, 1950 3 Sheets-Sheet 3 a E .151 I INVENTOR LOUIS H. MORIN ATTORN Y Patented Dec. 25, 1951 OFFICE.

METHOD or FORMING THREADED om- .CASTINGS Louis H. Morin, Bronx, N. Y.

Application June 16, 1950, Serial No. 168,616

25 Claims.

to the removal of the formed casting from the dies to be delivered to a trimming station where the casting is trimmed to produce a finished product. Still more particularly, the invention deals with a method of produoingdie castings which comprises supporting a forming member in die casting position relatively to the cavity of a die member to give a predetermined shape to a casting to be formed in the cavity, supporting the die member relatively to the forming member so that the cavity is closed, moving one of the'said The novel features of the invention will be best I understood from the following description when taken together with the accompanying drawings, in which selected embodiments of the invention are disclosed, and in which: s Fig. 1 comprises a schematic sectional view illustrating one method of carrying my invention into effect and indicating parts in different positions by dot and dash lines. 7 Figure 1a is a view partly in section, illustratinga modification of the method of Fig. 1. 7

Figs. 2 to 4, inclusive, are diagrammatic views illustrating steps in another modification, Fig. 4 beingan exploded view showing the ejected and trimmed casting.

Figs. '5-to '7 are sectional views diagrammatically illustrating successive steps in another modification.

Figs. 8 and 8a are diagrammatic sectional views illustrating a methodsimilar to that illustrated in Fig's. to 7. I Fig. 9 is a view illustrating another method similar to that shown in Figs. 5 to 7.

Fig. :10 is a' sectional view diagrammatically illustrating. another modification of the method of Figs. 5 to 7.

P Fig. 11 is a view similar to Fig. 10 showing another modified method, and N I Fig. 12 is a view illustrating a further modification.

In Fig. 1 I have diagrammatically illustrated at I 0, a plate of a casting machine having outwardly extending bearings H and I2 joined by a bracket 13 having a bearing portion l4. In the bearing [4 .is arranged a continuously driven shaft l5 carry- 2 ing on its inner end a bevel gear Hi. This gear meshes with another bevel gear I! keyed to a rod l8 slidable longitudinally in the hub of said gear, as is indicated by the key [9.

The rod I8 forms what might .be termed a core, or more generally classified as a thread forming member or element having at its lower end a reduced threaded portion, as indicated at 20. The gear I! is mounted to rotate in a supplemental bearing 2 I. The rod or member l8 has an upper threaded end 22*on which is mounted adjustment and lock nuts, as at 23, between which, and the top of the bearing II, is disposed a ballbearing 24. The purpose of this construction is to properly fix and position the threaded portion 20 within the cavity 25 of a pair of dies, one of which is shown at 26 in the drawing.

In illustrating one adaptation of my invention, the cavity 25 is so formed as to produce what might be termed a nut or cap 21 having an internal threaded sleeve portion 28 and an enlarged hexagon head 29. The cavity 25 also is shaped to form a portion 30, enlarged asseen at 3| .to receive the upper conical end 32 of a transfer finger 33. The finger 33 is pivoted, as seenat .34,

and when the dies areopened'and the member [8 freed from the casting, as later described, the finger will transfer the complete casting to.- a trimming station. The-cavity 25 also includes a gate forming portiori 35 through which the casting material is injected into the cavity from a suitable nozzle diagrammatically illustrated at 36.. When at the trimming station, the gate part 35', as well as the part 30 are trimmed from the casting, by suitable tools, not shown, as diagrammatically illustrated in dot and dash lines in the drawing.

Pivoted to the upper part of the bracket I3, as seen at 31, is a lever 38. The lever has along end 39 operating directly upon the upper end of the member [8, as clearlyseen, and the other forked end 49 of the lever has a block 4| pivoted thereto, as seen at 4| The block 3| is slidably mounted on a rod 42 pivoted to the bracket, as seen at 43. On the rod 42 is arranged a coil spring 44, which operates upon the block 4| to normally support the lever end 39 upon the end of the member l8, while at the same time, allowing the member It! to move upwardly against the action of the spring 44 in the operation of unthreading the member 18 from the casting 21. As previously stated, when the casting machin is in operation for intermittently producing castings, such as 21, the member I8 is constantly rotated in the direction of the arrow 45, the shaft I5 being driven in the direction of the arrow 46. Assuming that the member I8 has been adjusted so as to properly position the thread forming end 26 of said member within, or with respect to the cavity 25, the machine is now in position to form successive castings. The dies are first brought into abutting engagement with each other around the lower end ofthe member I8 and around the pin 33, then casting material is pressure injected into the cavity through the gate 35 to form the casting 21 and the internal thread 41 in the sleeve portion 28. Instantaneously upon the formation of the casting and said thread, the constant rotation of the member I8 will cause said member to feed upwardly, detaching the member I8 from the casting and simultaneously the dies are opened and the finger 33 moves the casting to the trimming station where the casting is trimmed. The part 30 including the enlargement 3| is stripped from the finger 33, the finger then returns to the full line position shown inthe drawing and the member I3 is returned by the spring 44 to its normal position, as shown in the drawing, and the next successive casting is formed upon a completion of the above With my improved method, by employing the constantly rotating core, the instant that's-olidification of the casting material takes place in the impression, the core, being rotated in a direction to unscrew itself from the threads of the casting, willthread out of the casting until the latter is free, at which time the dies are opened and the casting removed therefrom by the ejector finger, or in any other way. This method of procedure will produce clean threads in the casting and will adapt itself for producing threads on castings having relatively smalldiameters and where the castings as a whole may be relatively small.

In a more general sense, my invention may be said to comprise a method offorming a casting directly upon, or in association with a member which is in motion during the injection of the casting material into the cavity of the mold for any purpose whatever and where motion applied to the member is advantageous.

. In Fig. 1a of the drawing, I have diagrammatically shown a modification of the above described method to-the end of producing an externally threaded product such as a bolt, rather than aninternally threaded'product like the cap In Fig. 1a, H5 represents one of a pair of dies that are movable toward and from each other, each die having a cavity H6? for forming ahead II-I of hexagonal or other shape on the resulting casting or product H8, the die I I51havinga gate passage H9 for admission of casting material into the cavity H6 from an injection nozzle,

diagrammatically seen at I20. In addition to the gate H9, a further cavity I2I is provided in the die, ihtowhich extends a'transfer finger I22 for transferring the cast product H8 to a trimming station for removal of the portion I23 of the casting from the product proper H8.

At I24 is shown a rotating rod or forming member constituting part of the die elements for producing the product H8. The forming member is constantly rotated, as in the case of the member I8 in Fig. l, and fits in a recess or socket I25 in the dies. It has a threaded socket I28 which forms part of the complete die cavity H6 to produce the threaded part .121 of the resulting bolt.

The member I24 is constantly rotated as the casting material is injected into the complete die cavity so that when the casting material solidifies, the member I24 automatically moves vertically upward to free itself from the threaded portion I21. As in the method described in Fig. 1, when the dies I I5 are separated, the cast product H8, including the cast portion I23, is moved by the transfer pin I22 to a trimming station, not

shown, where the casting is trimmed.

From the foregoing description, it will appear that the two die parts H5, plus the'die member I24, together constitute die elements or cavity forming elements, and that oneof these elements is constantly rotated during the injection of casting material into thecavity.

In Figs. 2 to 4, inclusive, I have diagrammatically shown another method of forming an externall'y threaded cast product. In this case the product is in the form of a; set screw I28 havin a socket I29 of hexagonal or other shape at one end thereof. Here, I I5 may be a single die-member having'a'threaded'cavity I3I; I30 represents the gate passage, I26" the nozzle for'injection of casting material. The threaded cavity I3'I has at one end an enlarged bore I32 for reception or a. constantly rotating'rod member I33, within which is disposed an ejector pin I34. It will be understood thatthe member I33 may be rotated by any suitable means, including means similar to thatshown in Fig. 1. As will appear from 'a consideration of Figs. 2m 4, when the casting or product I28 is formed, the constant rotation of the member I33 will cause the casting I28 to be unthreaded out of the cavity I3I, in the'manner partially seen in Fig. 3. When the casting has been completely. unthreaded, the rotating member I33 may be moved. outwardly by means not shown until the ejector pin I34 strikes a suitable abutment I35 which will cause the cast product I28 to be displaced from the hexagonal portion I33 of the member I33, which formsthe hexagonal socket I29. On release or timely in the releaseof the product 123, the. gate portion I30'o1' the casting can be trimmed from the product I28. If desired, the casting can be transferred'to a trimming station for the trimming step. v

In Figs. 5, 6 and '7, I have diagrammatically shown another method of procedure in the formation of a domed hexagon nut product I36. sometimes termed an acorn nut. In said figures, I 31 represents a die supporting block; in which a circular die I38 is rotatably mounted. The die includes an annular gear portion I39 which meshes with a pinion I43 on a suitable drive shaft I4! so that the die'I38 can be constantly rotated. Channels I31 in the block I31 serve to conduct a cooling medium inheat exchange relation with the die I38.

At I42 is shown another cavity forming element comprising .primarily a threaded corepin I43for formingthethreaded'socket I36 of the product I36, the element I42 being mounted in a rack'bar I44 slidably mounted in a suitable support I45. The teeth I46 of the rackbar I44 are engaged by an intermittently rotated gear I41 also arranged in'the support I45. Gear I41, 'which'oscillates the rack bar, is power driven by means not shown.

At I38 is shown the cavity of the die I33 which is characterized to form the product I36. Opening into the cavity I33" is a gate passage I48, into and through which casting material is adapted to be injected from a suitable nozzle I49. At I53 is seenan ejector pin utilized for final displacement of the cast product I36 from the cavity I33.

With the method disclosed in Figs. to' 7, inclusive, it will be apparent that when the casting is formed, the constant rotation of the die I38 will cause the threaded core I43-to be displaced from the threaded bore I38 cf the product I36. To provide for this displacement, the rack I44 is moved outwardly, and" this movement is synchronized with the displacement of the core I43 from the bore I36, as by means of acarn and lever arrangement, not shown. The combination of these operations causes the product I36 to be partially removed from the cavity I33 111 the manner illustrated in Fig. 6. However, the core I43 becomes displaced from the socket I33 before the cast product I36 is fully removed from the cavity I38, and then in timely relationship the nozzle I49 is moved out of the path of the gate passage'l48 and the ejectorpin I56 then .passes into this passage and serves tofinally eject the casting in the manner illustrated in Fig. 7 of the drawing. V

It will be understood that in the particular -method just described the nut I36 need not nee essarily have a hexagonal shape, but may be square, etc., or may be provided with other keying means to enable it to rotate with the die I36.

In Fig. 8 of the drawing, I have shown a slight ,inodification of the method as illustrated in Figs. 5 to 7, inclusive, wherein I5I represents a circu-.

lar, rotatable die generally of the kind disclosed at I38, except as to the shape and contour of the cavity, and I52 represents a forming element,

similar to the element I43I4, but differing as that illustrated inFigs. 5 to 7, inclusive.

' In Fig. 8d, the method is the same as in Fig. 8. The only difierences are that in Fig. 8a the cavity in die I5I and the end of element I52 pro-v jecting into said cavity have diiferent shanes than the corresponding items in Fig. 8.

' In Fig. 9, I have shown another method of producing a nut-like product, similar to the product I36, of the method of Figs. 5 to '7, the only difference in the two methods being that, in Fig. 9,

i there is no rack and gear for moving the element I42. The latter is fixed in a member I56 arranged in asuitable stationary support I56. In this method, the die I51, including its associated die block and driving pinion, are suitably mountedby means not shown'so as to move relatively to the forming member or element I42 in the direction of the arrow I58, as partially illustrated 'in Fig. 9, in order to free the casting from the threaded portion I43. If the axial movement in the direction of the arrow I58 is greater than the speed of unthreading, the casting I5 9 will move :out of the die cavity I51 in the manner illus- "trated and can be finally ejected by a pin, as for example,"the pin I50 of Figs. 6 and '1. On the other hand, if the speed of axial movement parallels the unthreading speed, the casting will remain in the cavity I51 and can be ejectedby the ejector pin, as mentioned.

In Fig. 10 of the drawing, I have shown another method of procedure which is like the method disclosed in Figs. 5 to '1, inclusive, but differs primarily in the formation of a bolt-like cast product' I rather than the nut product I36. .In other words, the die I6I will have a thread forming cavity I62 and the rack member I44 will have a socket I63 of hexagon or other shape for formation of the head of the bolt I60. With this method, an ejector pin I64 is. employed in the rack Hi l to eject the casting I60 in accordance with the teachings in Fig. 4 of the drawing.

In Fig. 11 of the drawing is shown a modification of the method of Fig. 10, wherein 'a rack member I65, generally similar to the rack I44, is employed, except that a collar I66 is provided thereon, and between this collar and a support and guide I61 for the rack there is arranged a coil spring I63 to tensionally maintain the forming rack element I in engagement with the die I61. Also, the rack member I65 is not power driven, as in the methods of Figs. 5, 6, '1, and 10. 'The rack member is moved axially away from the die I6! by virtue of the unthread-ing action between the die and the casting, this axial movement taking place against the action of spring I68.

In Fig." 120i the drawing, I haveshown another method of procedure which employs the principle of rotation of both cavity forming members or elements, that is to say, the die member or element I69 and the core member or element I10. The latter includes a threaded core portion III, which is positioned ,within the cavity I69 of the 'die I69, as in the teachings in Figs. 5, 6, 7, and 9.

The die holder I12 has a shaft I13 extending through it, similar to the shaft MI, and on this shaft is disposed a large gear I14 which meshes with a smaller gear I15 on the die I69- On the shaft I13 is a pinion I16 which meshes with a large gear I11 to which the member or element I16 is attached. -With this construction, it will be apparent that the die member I69 will be r0,-

tated at a greater speed than the speed of rotation of the core member'l10;

' forming members I69 and I10, and one of these members is movableaxially of the other. Al-

'-' though both members are rotatable in the same direction, by rotating the die member at a faster speed and by synchronizing therewith the axial movement of the core member away from thedie member, the'casting I8I will be freed from both members and may be finally ejected from the die member by means of the ejector I82, after first loweringthe casting nozzle. By suitable gearing, as by interposing a gear between gears I14 and I15, or between pinion I1 and gear I11, the members I69 and I10 may also be rotated in opposite directions' From the several methods described, it will.

appear that in all instances at least two forming members cooperate with-each other to characterize the cavity formed betweenthem, which cavity defines the shape and characteristics of the re s-uiting casting. Atleast one of the cavity forming members is constantly rotated, and at the instant that solidification ofzthe casting material takesplace in the cavity,.the rotating member will cause the casting to be separated from. at least one of the. forming members.

' Castings having internal and external threads may be produced. In some instances, castings :having nov threads .may be formed by employing unthreaded forming members. The advantage of producing such castings by the present methods over methods using stationary unthreaded forming members is. that the castings will not freeze orshrink onto the forming members. The rotation, and the axial movement, of the unthreaded forming members will take place as described above in the methods using threaded forming members.

The present illustrations are simple forms to demonstrate the general principles of the invention. Other products besides nuts, bolts, or Allen set screws may, of course, be formed, depending upon the shape or contour of the forming members which are. employed. It will further :be apparent that threads of difierent kinds can bexiormed and that any suitable kind of casting material can be employed.

This. application is a continuation-impart of copending application Serial Number 714,187; filed Decemberd, 19.46,.now abandoned.

Having fully described my invention, what I claim as new and desire to secure by Letters Patout is:

l. The method of forming die castings including internal threaded portions, which comprises supporting a thread forming member in part of the mold cavity of a pair of relatively movable dies with the dies held in closed position around said member, rotating said member in the cavity, injecting casting material into said cavity while said member is rotating to form a casting with an internal thread shaped by the thread forming member, and removing said member from the casting by virtue of said rotation of said member, thereby screwing the same out of the thread formed in the casting.

2. The method of forming die castings including internal threaded portions, which comprises supporting a thread forming member in part of the. mold cavity of a pair of relatively movable dies. with the. dies held in closed position around said member, rotating said member in the die cavity, injecting casting material into said cavity while said member is rotating to form a casting with an internal thread shapedby the thread forming member, immediately removing said member from the casting by continuously rotating said member, thereby screwing thesame out of the thread formed in the casting, forming the casting on a transfer finger supported between said dies, and then opening the dies and removing the casting therefrom by said finger.

3. The method of forming die castings includ'-- ing internal threaded portions, which comprises supporting a thread forming member in partof the mold cavity of a pair of relatively movable dies with the dies held in closed position around said member, rotating said member in the die cavity, injecting casting material into said cavity while said member is rotating to form a casting with an internal thread shaped by the thread forming member, immediately removing said member from the casting by continuously rotating said member, thereby screwing the sameout of the thread formedin the casting, forming the casting on a transfer finger supported between said dies, then opening the dies and. removing the casting therefrom by said finger to a trimming station, and trimming the casting atsaid station.

4. The method of forming diev castings having threaded portions, which comprisessupporting, a thread forming member within the cavity of a pair ofdies when in closed position, rotating said member withinthe dies, injectingcasting material into the die cavity to form therein and on said rotating member a casting having threads shaped by said member, and removing the member from the casting by unscrewing the same therefrom by virtue of said rotation of said member.

5. The method of producing a threaded die casting, which comprises adjustably supporting a thread forming member with respect to the cavity of. a pair of dies to predeterminedly posi tion the member insaid cavity, pressure injecting casting material into said cavity with the dies in closed positionwhile constantly rotatingsaid thread forming member inia direction to unscrew the member from the thread formed thereby, immediately unthreading the member from'the resulting casting upon solidification of the same, and then separating the diesand removing the casting with the formed thread thereon from the position between the dies.

6. The method of forming die castings, which comprises supporting a member in the cavity of a pair of relatively movable dies to give predetermined shape to a casting to be formed in said cavity, supporting the dies in closed position around said member, constantly moving the member within the die cavity while pressure injecting casting material into the cavity to form a casting on said member, and freeing saidcasting with respect to the member by the constant movement imparted thereto.

7. In the art of forming die castings upon a core contributing predetermined structural characteristics to the resulting casting, the method which comprises yi'eldably and adjustably' sup porting a core in predetermined position within the cavity of a pair of dies, constantly rotating the core between the'dies in closed'position while injecting casting material into the die cavity to form a casting on that part of the core supported therein, freeing the core instantaneously from the casting by continuously rotating said core, and feeding the core out of the casting' to free the castingfor ejection from the cavities during movement. of the dies into open position.

8. The method of forming die castings, which comprises supporting a member in'the cavity of a pair of relatively movable dies to give predeterminedshape to a casting to be formed in said cavity, closing the dies around said member, constantly rotating the member within the die cavity while. pressure injecting casting material into the cavity to form a casting on said member, and constantly rotating, said member to free it from the casting fiormed thereon.

9.. The method of forming die castings, which comprises supportinga core member and an ejector member in the cavity of a pair of rel atively movable dies togive predetermined shape to a casting to. be formed in said cavity, supporting the dies in closed position around said members, constantly moving the core member between. the dies andwithin the die cavity while pressure injecting castingkmaterial into the cavmember, and freeing said casting with respect to the member-by said movement imparted thereto.

11. The method of forming die castings which comprises continuously moving a core between aQpair of relatively, movable dies having mating cavities, closing the dies about said moving core so that at least a portion thereof moves Within the die cavities, injecting molten casting material into said cavities and in contact with the moving core, continuing to move the core as the casting material solidifies, thereby freeing thecore from the resulting casting, opening the dies and ejecting the casting therefrom.

12. The method of forming die castings which comprises positioning a core and an ejector within the die cavities of a pair of relatively movable dies having mating cavities, injecting molten casting material into said cavities and in contact with said core and ejector to form a casting attached to the core and to the ejector, freeing the core from the casting by moving the core relatively thereto, opening the dies and ejecting the casting therefrom by moving said ejector having the casting attached thereto, trimming the casting on the ejector, and then stripping the casting from the ejector.

13. The method of forming die castings, which comprises supporting a member in the cavity of in the cavity of a die member to give predetermined shape to a casting to be formed in said cavity, closing the dies around said member, constantly rotating the member within the die cavity while pressure injecting casting material into the cavity to form a casting on said member, and constantly rotating said member to free the casting formed thereon from the dies.

14. The method of forming die castings, which comprises supporting a member in the cavity of a pair of relatively movable dies to give predetermined shape to a casting to be formed in said cavity, supporting the dies in closed position around said member, moving the member within the die cavity while pressure injecting casting material into the cavity to form a casting on said member, and freeing said casting with respect to the dies by said movement imparted to the member.

15. The method of producing die castings which comprises supporting a forming member in the cavity of a die member to give a predetermined shape to a casting to be formed in said cavity, supporting the die member relatively to the forming member so that the cavity is closed, moving one of said members relatively to the other while pressure injecting casting material into the cavity to form a casting, and freeing said casting from at least one of said members by said movement imparted to the moving member.

16. The method of producing die castings which comprises supporting a forming member in die casting position relatively to the cavity of a threaded portions comprising supporting a core die member to give predetermined shape to ,a casting to be formed in said cavity, supporting the die member relatively to the forming member so that. the cavity is closed, moving one of said members relatively to the other while pressure injecting casting material into the cavity to form a casting, and freeing said casting from at least one of said members by said movement imparted to the moving member.

17. The method of forming an externally threaded die casting, which comprises supporting a forming member in die casting position relatively to a die member to collectively form between said members a cavity in which said casting is to be formed, one of said members being threaded so that the surfaces of the cavity are threaded at least in part, supporting said members in engagement with each other, rotating one of said members in said engagement while simultaneously pressure injecting casting material into the cavity to form a casting, and freeing said casting from at least one of said membe'rs'by virtue of the rotary movement imparted to' the said rotating member.

18. The method of forming castings having member in the cavity of a die member to give a predetermined contour to a casting to be formed in said cavity, one of said members being threaded, pressure injecting casting material into the cavity while constantly rotating said die memberto form said casting, and utilizing the rotary motion of the die member as a means for freeing the casting by unthreading the latter from one of said members.

19. The method of forming castings having threaded portions comprising supporting a core member in the cavity of a die member to give a predetermined contour to a casting to be formed in said cavity, one of said members being threaded, pressure injecting casting material into the cavity while constantly rotating said die member to form said casting, utilizing the rotary motion of the die member as a means for freeing the casting by unthreading the latter from one of said members, and during said unthreading step moving the core member axially with respect to said die member.

20. The method of forming castings having threaded portions comprising supporting a core member in the cavity of a die member to give a predetermined contour to a casting to be formed in said cavity, one of said members being threaded, pressure injecting casting material into the cavity while constantly rotating both of said members, and utilizing the rotary motion of said members as a means for freeing the formed casting by unthreading the latter from one of said members.

21. The method of forming die castings which comprises supporting a forming member in die casting position relatively to the cavity of a die member to form by the die member and forming member a cavity characterizing the product to be cast, moving both of said members while pressure inject ng casting material into the cavity to form a casting, and freeing the casting relatively to both members by virtue of the movement imparted to said members.

22. The method of forming die castings which comprises supporting a forming member in die casting position relatively to the cavity of a die member to form by the die member and forming member a cavity characterizing the product to be cast, rotating both of said memberswhile pres- TI sure injecting, casting material into the cavity to form" a casting; freeingthe casting from one of said members by vi'rtue of the rotary movement imparted td said members, and imparting an axial movement to one: of said members to eject the casting from: the other member.-

23. The method of forming an externally threaded die casting which comprises supporting a forming member in die casting position relatively to a threaded diermembei" torcollectively form between said members: a threaded cavity in which said; casting is 'to be formed; supporting said members in engagement with each other, continuously rotating the forming member while it is in engagement with the die member, prescasting which comprises supporting a forming member in die casting position relativelyto a die member; one of, said members being threaded to collectively formv between said members a threaded cavity in which said casting is to be formed, supporting" said members in engagement with each other, continuously rotating the die member while it is irrengagement' withthe iormeing member; pressure injecting casting material intothe cavity while said die member is being continuously'rotated, thereby'f'orming a: threaded casting in the cavity; unthreading the casting from the formingmember by virtue of the rotary movement imparted. to the die member; and simultaneously with said unthreading step moving the formingmember axially with respectto'fthe rotating die member..

25. The method of forming athreadeddie casting which. comprises sugporting a, forming: member in die casting" position relatively to. a die member, one of said membersbeingithreaded' to collectively form betweensaid members a thread;- ed cavity in which said casting is. to be. formed, supporting said members in engagement with each other,, continuously rotating. the die member while. it is in engagement. with. the forming membenfpressure injecting casting materialinto the cavity while said. die memberis being, continuously rotated, thereby forming a threaded casting in the cavity, unthreading' the casting. from the, forming member by virtue of the. rotary movement imparted to the die. memb'en, and s1;- multaneously with said unthreadi'ngzstep moving the die member axially away from the forming member. I

LOUIST H. MORINL,

No references cited. 

